It is hypothesized that there will be a change in the diffusion signal measured with DKI in the thalamus (THA) and with DTI in the corpus callosum (CC), in the acute stage and at follow-up of the mTBI subjects compared with the healthy controls. Secondary it is expected that there will be changes in the diffusion signal measured with DKI and DTI in other WM and GM area in both the acute stage and at follow up with mTBI subjects compared with healthy controls. Also rs-fMRI markers are secondary expected to differ in the two groups. Moreover secondarily the MRI markers are tested for correlation with the severity of PCS acutely and at follow up after mTBI.